Roast-reductive leach process for copper recovery
AssigneeThe International Nickel Company, Inc.
InventorsVictor A. Ettel, Eric A. P. Devuyst, Ramamritham Sridhar, Charles E. O'Neill
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Abstract
A sulfide containing copper and one or more of iron, nickel and cobalt, is dead-roasted at a temperature of 750.degree. C or above, then subjected to a pressure leach under reducing conditions to produce elemental copper and an aqueous solution of the other metals.
Claims7
A process for recovering copper from a particulate sulfide-containing material which contains in addition to said copper at least one other metal selected from the group consisting of iron, nickel and cobalt, comprising roasting said material at a temperature of at least about 750.degree. C. for a period of sufficient duration to provide a substantially sulfur-free calcine, forming a slurry of said calcine with water or an aqueous solution containing at least a sufficient amount of sulfuric acid to supplement any sulfuric acid formed in situ and satisfy the stoichiometry of formation of sulfates of said other metal(s), heating said slurry to a temperature of at least about 110.degree. C. under superatmospheric pressure in the presence of a reducing gas to sulfate said other metal(s) and reduce said copper to elemental form, and separating the product of said pressure-heat treatment into a liquor containing said other metal(s) and a solids residue containing said elemental copper.
Dependencies are inferred from the claim text.